---

2011-10-12

Code snippets from Adam Hartz for time-limiting a Python child process:

def setlimits():

"""

Helper to set CPU time limit for check_code, so that infinite loops

in submitted code get caught instead of running forever.

"""

resource.setrlimit(resource.RLIMIT_CPU, (10, 10))

def check_python_code(code):

#TODO: Investigate pypy for sandboxing

"""

Run the given code; outputs a tuple containing:

the program's output (stdout), error messages (stderr)

"""

python = subprocess.Popen(["python"],stdin=subprocess.PIPE,\

stdout=subprocess.PIPE,\

stderr=subprocess.PIPE,\

preexec_fn=setlimits)

PY_PROCESS_LOCK.acquire()

output = python.communicate(code)

PY_PROCESS_LOCK.release()

return output